diff --git a/src/supervisor-update.coffee b/src/supervisor-update.coffee
index 1506ff94..93074e81 100644
--- a/src/supervisor-update.coffee
+++ b/src/supervisor-update.coffee
@@ -21,18 +21,14 @@ exports.update = ->
 		console.log('Fetching updated supervisor:', updateImage)
 		docker.createImageAsync(fromImage: updateImage)
 	.then (stream) ->
-		deferred = Promise.defer()
+		return new Promise (resolve, reject) ->
+			if stream.headers['content-type'] is 'application/json'
+				stream.pipe(JSONStream.parse('error'))
+				.pipe(es.mapSync(reject))
+			else
+				stream.pipe(es.wait((error, text) -> reject(text)))
 
-		if stream.headers['content-type'] is 'application/json'
-			stream.pipe(JSONStream.parse('error'))
-			.pipe es.mapSync (error) ->
-				deferred.reject(error)
-		else
-			stream.pipe es.wait (error, text) -> deferred.reject(text)
-
-		stream.on 'end', -> deferred.resolve()
-
-		return deferred.promise
+			stream.on('end', resolve)
 	.then ->
 		console.log('Tagging updated supervisor:', updateImage)
 		docker.getImage(updateImage).tagAsync(